Ring-containing modified resins and dispersants including it

ABSTRACT

The ring-containing modified resin is represented by the following chemical formula (1) 
 
R 1 [—(—O—CO—NH—R 2 —NH—CO—O—R 3 —) p —O—R 4 ] q   (1) 
 
(in the chemical formula (1), R 1  is a dehydroxyl residue of a resin having a benzene ring and/or a condensed ring and hydroxyl group: 
     —R 2 — is deisocyanate group derived from an organic diisocyanate:    —R 3 — is a dehydroxyl residue of polyol having number-average molecular weight of 200 to 30000: p is 1 to 3:    —R 4  is a hydrogen atom, alkyl group having 1 to 18 carbons, phenyl group:    q is the same number as the number of the dehydroxyl residue of R 1 ).

TECHNICAL FIELD

This invention relates to a modified resin for using as a dispersant forpreparing paint and dispersion liquid which pigments or fine particlesare dispersed homogeneously.

BACKGROUND ART

A nonaqueous paint comprises pigment, a resin for forming a coat, and anorganic solvent. If the pigment is not dispersed homogeneously in thepaint, the pigment aggregates and precipitates while storing the paintfor a long time, and it causes a color separation, a color float or alowering a gloss when painting. Therefore, a dispersant for dispersingthe pigment homogeneously is added to the paint.

As such dispersant, (meth)acrylic type block copolymer which(meth)acrylic acid monomer containing amino group or (meth)acrylatecontaining ammonium group block-polymerizes with (meth)acrylate andmacromonomer containing terminal (meth)acryloyl group, is mentioned inJapanese Patent Provisional Publication No. 2002-322226. The amino groupor the ammonium group in the copolymer interacts with the pigmentstrongly, and makes the pigment disperse in the copolymer.

Generally, the dispersant has a pigment affinity part and a resinaffinity part, and a basic group or an acidic group acts as the pigmentaffinity. However, when the dispersant including the basic group isused, the preservation stability of a silanol-including low-pollutiontype paint falls, or hardening of the baking paint using an acidcatalyst is inhibited. On the other hand, when the dispersant includingthe acidic group with high acid value is used, viscosity of the paintincreases, or the preservation stability of the paint falls. In otherfields instead of the field of the paint such as an electronic material,addition of dispersant including the acidic group or the basic grouptends to be avoided because the charge thereof affects the electronicmaterial.

The present invention has been developed to solve the foregoingproblems. It is an object of the present invention to provide aring-containing modified resin having a benzene ring and/or a condensedring which has no possibility of affecting stability or hardening ofpaint and a coating material, as a pigment affinity part. Thering-containing modified resin is used as a dispersant for dispersingthe pigment and fine particles sufficiently homogeneously. It is anotherobject of the present invention to provide a dispersant including it.

DISCLOSURE OF INVENTION

The ring-containing modified resin of the present invention developedfor accomplishing the foregoing object, is represented by the followingchemical formula (1)R¹[—(—O—CO—NH—R²—NH—CO—R³—)_(p)—O—R⁴]_(q)  (1)(in the chemical formula (1), R¹ is a dehydroxyl residue of a resinhaving a benzene ring and/or a condensed ring and hydroxyl group:—R²— is deisocyanate group derived from an organic diisocyanate:—R³— is a dehydroxyl residue of polyol having number-average molecularweight of 200 to 30000:p is 1 to 3:—R⁴ is a hydrogen atom, alkyl group having 1 to 18 carbons, phenylgroup:q is the same number as the number of the dehydroxyl residue of R¹).

The resin having the benzene ring and/or the condensed ring and hydroxylgroup is selected from the group consisting of a rosin derivativeincluding hydroxyl group, a xylene resin including hydroxyl group, astyrene resin including hydroxyl group. Concretely, as the rosinderivative including hydroxyl group, PINECRYSTAL D-6011 havingnumber-average molecular weight of 910, PINECRYSTAL D-6240 havingnumber-average molecular weight of 3500, PINECRYSTAL D-6154 havingnumber-average molecular weight of 1760, that are available from ArakawaChemical Industries, Ltd., are mentioned. As the xylene resin includinghydroxyl group, NIKANOL K-140 having a hydroxyl value of 290, NIKANOLK-100 having a hydroxyl value of 90, that are available from MitsubishiGas Chemical Company, Inc., are mentioned. As the styrene resinincluding hydroxyl group, MACROMONOMER HS-6 having number-averagemolecular weight of 6000 which is polystyrene including dihydroxylgroup, MACROMONOMER HN-6 having number-average molecular weight of 6000which is a copolymer of styrene including dihydroxylgroup/acrylonitrile, that are available from Toagosei Co., Ltd., arementioned.

The part of the benzene ring and/or the condensed ring in thering-containing modified resin acts as the pigment affinity part of thedispersant. In the benzene ring and/or the condensed ring, pi-electronexists at delocalization state, so this conjugated system leads tointeraction to the pigment, and the pigment can be dispersedsufficiently.

The organic diisocyanate is selected from the group consisting of anaromatic diisocyanate, an aliphatic diisocyanate, an alicyclicdiisocyanate. Concretely, as the aromatic diisocyanate,tolylenediisocyanate (TDI), 4,4′-diphenylmethanediisocyanate (MDI),1,5-naphthalenediisocyanate, are mentioned. As the aliphaticdiisocyanate, hexamethylenediisocyanate (HMDI) is mentioned. As thealicyclic diisocyanate, isophoronediisocyanate (IPDI),1,3-bis(isocyanatemethyl)cyclohexane are mentioned. It is preferablethat tolylenediisocyanate (TDI) is used.

The polyol is selected from the group consisting of polyether polyol,polyester polyol, an acrylic copolymer including hydroxyl group.Concretely, as the polyether polyol, polyethylene glycol, polypropyleneglycol, poly(oxyethylene) poly(oxypropylene) alkyl ether, poly(butyleneflycol) are mentioned. As the polyester polyol, epsilon-caprolactonpolymer, poly(12-hydroxystearic acid) are mentioned.

The acrylic copolymer including hydroxyl group is prepared bycopolymerizing acrylates using a polymerization adjustment agentincluding the hydroxyl group such as 2-mercaptoethanol, and the hydroxylgroup is introduced to the terminal of the copolymer. Concretely, acompound which the hydroxyl group was introduced to the terminal ofpoly(lauryl methacrylate), is mentioned.

The polyol having the number-average molecular weight of 200 to 30000 isused. Especially, it is further preferable that the polyol having thenumber-average molecular weight of 1000 to 15000 is used. If thenumber-average molecular weight is less than 200, the dispersion speedand the dispersion stability of the pigment may fall. If thenumber-average molecular weight is more than 30000, the viscosity of thedispersant increases too much, so it is hard to deal with.

The ring-containing modified resin of the present invention is preparedby carrying out the addition reaction or the polyaddition reaction ofthe organic diisocyanate and the polyol to the resin having the benzenering and/or the condensed ring and hydroxyl group.

The dispersant of the present invention comprises the ring-containingmodified resin. For example, the dispersant is prepared by dissolvingthe ring-containing modified resin into the inactive solvent. Forexample, the dispersant is used as the dispersant for pigment for paint,the dispersant for fine particles for a coating material, the dispersantfor fine particles for sintering.

It is preferable that the inactive solvent can dissolve the producedring-containing modified resin and can mix with the paint or the ink.Concretely, an aliphatic solvent such as n-hexane; an aromatic solventsuch as xylene, solvesso100, solvesso150; a ketone type solvent such asmethyl isobutyl ketone; an ester type solvent such as ethyl acetate,butyl acetate; a cellosolve type solvent such as butyl cellosolve, ethylcellosolve; a propylene glycol type solvent such as propylene glycolmonomethyl ether; a cellosolve acetate type solvent such as ethyleneglycol monoethyl ether acetate; a propylene glycol monoalkyl etheracetate type solvent such as propylene glycol monomethyl ether acetate;are mentioned. These solvents may be used solely or plurally by mixing.

MODE FOR CARRYING OUT THE INVENTION

Hereunder, an applying example that the ring-containing modified resinapplying the present invention is prepared, is explained. And acomparative example that the modified resin not applying the presentinvention is prepared, is explained.

Applying Example

30 parts by weight of propylene glycol monomethyl ether and 3.48 partsby weight of TDI were added to a vessel equipping a reflux condenser, athermometer, a stirrer and a dropping tank, and the liquid temperaturewas maintained at 60 degrees centigrade. Mixture of 20 parts by weightof MPEG1000 which is methoxypolyethylene glycol having 1000 of molecularweight, that is available from Toho Chemical Industry Co., Ltd., and 30parts by weight of propylene glycol monomethyl ether was dropped to thevessel while an hour. It was reacted for an hour at 60 degreescentigrade. Then Mixture of 11.9 parts by weight of NIKANOL K-100 whichis the xylene resin including hydroxyl group, that is available fromMitsubishi Gas Chemical Company, Inc., and 15.7 parts by weight ofpropylene glycol monomethyl ether was dropped to the vessel while anhour. After dropping, it was reacted for two hours at 60 degreescentigrade to synthesize the modified xylene resin. The number-averagemolecular weight of prepared modified xylene resin was determined by gelpermeation chromatography, and it was 24200. The acid value and theamine value of prepared modified xylene resin were measured, and both ofthem were 0.

Comparative Example

50 parts by weight of xylene was added to a vessel equipping a refluxcondenser, a thermometer, a stirrer and a dropping tank, and the liquidtemperature was maintained at 100 degrees centigrade. Mixture of 15parts by weight of LIGHT ESTER DM which is dimethylamino ethylmethacrylate, that is available from Kyoeisha Chemical Co., Ltd., 30parts by weight of ethyl acrylate, 15 parts by weight of MACROMONOMERAA-6 which is methyl methacrylate macromonomer having 6000 ofweight-average molecular weight, that is available from Toagosei Co.,Ltd., 0.5 parts by weight of dodecyl mercaptan and 1 part by weight ofazobisisobutyronitrile was dropped to the xylene while three hours undera nitrogen gas atmosphere. After dropping, 0.5 parts by weight ofazobisisobutyronitrile was further added. It was reacted for two hoursat 100 degrees centigrade to synthesize the (meth)acrylic copolymerincluding amino group. The number-average molecular weight of preparedcopolymer was determined by gel permeation chromatography, and it was23000. The acid value and the amine value of prepared copolymer weremeasured, and the acid value was 0, the amine value was 19.

Examination Example 1

In order to investigate the physical properties of the main component ofthe paint using the modified xylene resins of Applying Example orComparative Example, the paint was prepared, and the viscosity, theaggregation of the pigment, the gloss of coated film by measuring thegloss of 20 degrees and stability for a silanol-including resin, weremeasured.

(Preparing the Paint and Evaluation)

The main component of the paint was prepared using the modified xyleneresins of Applying Example or Comparative Example. 1.35 g of themodified xylene resin of Applying Example or Comparative Example, 34 gof ACRYDIC A-801 which is toluene-butyl acetate solution of an acrylicpolyol resin having hydroxyl value of 50 as 50% of non-volatilecomponent, that is available from Dainippon Ink And Chemicals, Inc., 4.5g of FW-200 as the carbon black that is available from Degussa, 19.0 gof thinner which the ratio of xylene to butyl acetate was 70 to 30 and200 g of glass beads having the diameter of 1.5 to 2.0 mm were added toa 225 ml glass bottle. It was stirred with a paint shaker that isavailable from Red Devil Company for an hour. After an hour, 71.6 g ofACRYDIC A-801 was added, and the letdown thereof was executed. The glassbeads were filtrated out to prepare the main component of the paint.

Furthermore, a silanol resin sample for evaluating the stability to thesilanol-including resin was prepared using the main component of thepaint. 60 parts by weight of xylene was added to a vessel equipping areflux condenser, a thermometer, a stirrer and a dropping tank, and theliquid temperature was maintained at 100 degrees centigrade. Mixture of20 parts by weight of gamma-methacryloxypropyltrimethoxysilane, 20 partsby weight of lauryl methacrylate, and 1 part by weight ofazobisisobutyronitrile was dropped to the xylene while an hour under anitrogen gas atmosphere. After dropping, 0.5 parts by weight ofazobisisobutyronitrile was further added. It was reacted for two hoursat 100 degrees centigrade to synthesize the (meth)acrylic copolymerincluding silanol group. 30 g of the prepared copolymer and 0.6 g of theabove main component of the paint were added to a 140 ml glass bottle.It was stirred with a paint shaker that is available from Red DevilCompany for 15 minutes to prepare the silanol resin sample.

The measurement of the viscosity was executed by following method. Therate of shear per 1 second, 10 seconds, 100 seconds and 1000 secondswere measured using a viscoelasticity measuring instrument of catalogNo. Physica MCR 300 that is available from PHYSICA-Messtechnik GmbH, andthe viscosity of the main component of the paint was evaluated.

The observation of the aggregation of the pigment was executed byfollowing method. 10 g of the main component of the paint was added to a50 ml screw tube having diameter of 35 mm and height of 78 mm. An innerwall of the tube was wetted with the main component of the paintsufficiently. After keeping the tube at stationary state for 24 hours,the inner wall of the tube was observed by visual observation, and theaggregation of the pigment was evaluated.

The measurement of the gloss of coated film was executed by followingmethod. 100 parts by weight of the main component of the paint and 17.6parts by weight of SUMIDUR N-75 that is available from Sumitomo BayerUrethane Co., Ltd. as the hardener were mixed. The mixture was dilutedwith the thinner which the ratio of xylene to butyl acetate was 70 to30, and the viscosity thereof by using a Ford cup No. 4 was adjusted to12 seconds. The diluted paint was sprayed onto a tin-plate by air spray,and air-dried for 24 hours. After drying, the gloss of 20 degrees of thecoated plate was measured using a glossmeter that is available fromBYK-Gardner, and the gloss thereof was evaluated.

Stability for the silanol-including resin was evaluated by visualobserving the change of the silanol resin sample which was kept atstationary state for a week at 50 degrees centigrade.

In addition, a blank examination was executed for comparison. As ablank, the main component of the paint was prepared by the similarprocedure of Applying Example except for using no ring-containing resin,and the viscosity, the aggregation of the pigment, the gloss of coatedfilm by measuring the gloss of 20 degrees and stability forsilanol-including resin were measured.

The results are respectively shown in Table 1. TABLE 1 ViscosityAggregation Gloss of Stability for 1 s⁻¹ 10 s⁻¹ 100 s⁻¹ 1000 s⁻¹ ofPigment 20 deg. Silanol resin Applying 270 266 260 230 Nothing 96.5 NoExample Change Comparative 840 790 400 250 Nothing 92.2 Gelation ExampleBlank 56000 5240 777 254 Aggregation 85.7 No Change

As shown in Table 1, it is clear that the paint of Applying Example haslower viscosity, no aggregation of the pigment onto the inner wall ofthe bottle, the improved gloss of coated film, and excellent stabilityfor silanol-including resin, compared with the paint of the ComparativeExample and the paint of the blank resin.

Examination Example 2

In order to investigate dispersibility of the fine particles to themodified xylene resins of the Applying Example and the ComparativeExample, dispersion liquid of the fine particles was prepared and adiameter of the fine particle was measured.

The dispersion liquid of the fine particles was prepared using themodified xylene resins of the Applying Example and the ComparativeExample. First, 1.80 g of the modified xylene resin of Applying Exampleor Comparative Example, 24 g of methoxypropyl acetate, 6 g of fineparticle titanium oxide of catalog No. STR-100A as the fine particle,which has 0.01 microns of primary particle size, that is available fromSakai Chemical Industry, Co., Ltd., and 30 g of glass beads having thediameter of 1.5 to 2.0 mm were added to a 140 ml glass bottle. It wasstirred with a paint shaker that is available from Red Devil Company foran hour. After an hour, the glass beads were filtrated out to preparethe dispersion liquid of the fine particle titanium oxide.

The particle size of the fine particle is measured by a particle sizedistribution measuring instrument of catalog No. LB-500 that isavailable from Horiba, Ltd., and a median size thereof is calculated.

The result is shown in Table 2. TABLE 2 Median Size (micron) ApplyingExample 0.030 Comparative Example 0.090 Blank 4.500

As shown in Table 2, it is clear that the dispersion liquid using themodified xylene resin of the Applying Example has a small median sizeand excellent dispersibility, compared with the dispersion liquid usingthe modified xylene resin of the Comparative Example and the dispersionliquid using the blank resin.

Examination Example 3

In order to investigate dispersibility of sintering fine particles tothe modified xylene resins of the Applying Example and the ComparativeExample, dispersion liquid of the sintering fine particles was preparedand the viscosity thereof was measured.

As the sintering fine particles, Ni—Zn—Cu type ferrite powder was used.The modified xylene resin of the Applying Example or the ComparativeExample was dissolved in 60 parts by weight of the water toward the 100parts by weight of the ferrite powder. Media and the ferrite powder wereadded to the solution under stirring, and were dispersed. Then they werecrushed with a ball mill, to obtain slurry. 13 parts by weight ofacrylic emulsion at solid content toward 100 parts by weight of theferrite powder was added to the slurry. It was stirred and mixed, andceramic slurry was manufactured.

The dispersion state of the ceramic slurry was evaluated using agrindgauge. A board which had a trench that the depth of an end was 50microns and that of the other end was 0 micron was prepared. When apaste on the board was scratched from a portion of the depth of 50microns toward a portion of the depth of 0 micron horizontally, a lengthof a scratch was observed. It was evaluated by classifying followingthree standards: if the length was less than 2 microns, it was indicatedby O, if the length was ranging from 2 microns to 5 microns, it wasindicated by Δ, if the length is more than 5 microns, it was indicatedby X.

The result is shown in Table 3. TABLE 3 Value of Grindgauge ApplyingExample ◯ Comparative Example Δ Blank X

As shown in Table 3, it is clear that the dispersion liquid using themodified xylene resin of the Applying Example has a lower value ofgrindgauge and excellent dispersibility, compared with the dispersionliquid using the modified xylene resin of the Comparative Example andthe dispersion liquid using the blank resin.

As explained in detail, the ring-containing modified resin of thepresent invention is an effective compound for dispersing the pigmentand the fine particles homogeneously. The ring-containing modified resinhas the benzene ring and/or the condensed ring, not carboxyl group oramino group, as the pigment affinity part, so it has no possibility ofaffecting the stability or the hardening of the paint and the coatingmaterial.

When the paint that the pigment is dispersed using the modified resin isapplied, the coated film having the gloss and no uneven coloring will beobtained.

Moreover, in the dispersant that the fine particles for coating materialor the fine particles for sintering are dispersed using the modifiedresin, these fine particles have a small particle size.

1. A ring-containing modified resin represented by the followingchemical formula (1)R¹[—(—O—CO—NH—R²—NH—CO—O—R³—)_(p)—O—R⁴]_(q)  (1) (in the chemicalformula (1), R¹ is a dehydroxyl residue of a resin having a benzene ringand/or a condensed ring and hydroxyl group: —R²— is deisocyanate groupderived from organic diisocyanate: —R³— is a dehydroxyl residue ofpolyol having number-average molecular weight of 200 to 30000: p is 1 to3: —R⁴ is a hydrogen atom, alkyl group having 1 to 18 carbons, phenylgroup: q is the same number as the number of the dehydroxyl residue ofR¹)
 2. The ring-containing modified resin according to claim 1, whereinthe resin having the benzene ring and/or the condensed ring and hydroxylgroup is selected from the group consisting of a rosin derivativeincluding hydroxyl group, a xylene resin including hydroxyl group, astyrene resin including hydroxyl group.
 3. The ring-containing modifiedresin according to claim 1, wherein the organic diisocyanate is selectedfrom the group consisting of an aromatic diisocyanate, an aliphaticdiisocyanate, an alicyclic diisocyanate.
 4. The ring-containing modifiedresin according to claim 1, wherein the polyol is selected from thegroup consisting of polyether polyol, polyester polyol, acryliccopolymer including hydroxyl group.
 5. A dispersant for pigment forpaint comprising a ring-containing modified resin represented by thefollowing chemical formula (1)R¹[—(—O—CO—NH—R²—NH—CO—O—R³—)_(p)—O—R⁴]_(q)  (1) (in the chemicalformula (1), R¹ is a dehydroxyl residue of a resin having a benzene ringand/or a condensed ring and hydroxyl group: —R₂— is deisocyanate groupderived from an organic diisocyanate: —R³— is a dehydroxyl residue ofpolyol having number-average molecular weight of 200 to 30000: p is 1 to3: —R⁴ is a hydrogen atom, alkyl group having 1 to 18 carbons, phenylgroup: q is the same number as the number of the dehydroxyl residue ofR¹).
 6. The dispersant for the pigment for the paint according to claim5, wherein the resin having the benzene ring and/or the condensed ringand hydroxyl group is selected from the group consisting of a rosinderivative including hydroxyl group, a xylene resin including hydroxylgroup, a styrene resin including hydroxyl group.
 7. The dispersant forthe pigment for the paint according to claim 5, wherein the organicdiisocyanate is selected from the group consisting of an aromaticdiisocyanate, an aliphatic diisocyanate, an alicyclic diisocyanate. 8.The dispersant for the pigment for the paint according to claim 5,wherein the polyol is selected from the group consisting of polyetherpolyol, polyester polyol, acrylic copolymer including hydroxyl group. 9.A dispersant for fine particles for a coating material comprising aring-containing modified resin represented by the following chemicalformula (1)R¹[—(—O—CO—NH—R²—NH—CO—O—R³—)_(p)—O—R⁴]_(q)  (1) (in the chemicalformula (1), R¹ is a dehydroxyl residue of a resin having a benzene ringand/or a condensed ring and hydroxyl group: —R²— is deisocyanate groupderived from an organic diisocyanate: —R³— is a dehydroxyl residue ofpolyol having number-average molecular weight of 200 to 30000: p is 1 to3: —R⁴ is a hydrogen atom, alkyl group having 1 to 18 carbons, phenylgroup: q is the same number as the number of the dehydroxyl residue ofR¹).
 10. The dispersant for the fine particles for the coating materialaccording to claim 9, wherein the resin having the benzene ring and/orthe condensed ring and hydroxyl group is selected from the groupconsisting of a rosin derivative including hydroxyl group, a xyleneresin including hydroxyl group, a styrene resin including hydroxylgroup.
 11. The dispersant for the fine particles for the coatingmaterial according to claim 9, wherein the organic diisocyanate isselected from the group consisting of an aromatic diisocyanate, analiphatic diisocyanate, an alicyclic diisocyanate.
 12. The dispersantfor the fine particles for the coating material according to claim 9,wherein the polyol is selected from the group consisting of polyetherpolyol, polyester polyol, acrylic copolymer including hydroxyl group.13. A dispersant for fine particles for sintering comprising aring-containing modified resin represented by the following chemicalformula (1)R¹[—(—O—CO—NH—R²—NH—CO—O—R³—)_(p)—O—R⁴]_(q)  (1) (in the chemicalformula (1), R¹ is a dehydroxyl residue of a resin having a benzene ringand/or a condensed ring and hydroxyl group: —R²— is deisocyanate groupderived from an organic diisocyanate: —R³— is a dehydroxyl residue ofpolyol having number-average molecular weight of 200 to 30000: p is 1 to3: —R⁴ is a hydrogen atom, alkyl group having 1 to 18 carbons, phenylgroup: q is the same number as the number of the dehydroxyl residue ofR¹).
 14. The dispersant for the fine particles for the sinteringaccording to claim 13, wherein the resin having the benzene ring and/orthe condensed ring and hydroxyl group is selected from the groupconsisting of a rosin derivative including hydroxyl group, a xyleneresin including hydroxyl group, a styrene resin including hydroxylgroup.
 15. The dispersant for the fine particles for the sinteringaccording to claim 13, wherein the organic diisocyanate is selected fromthe group consisting of an aromatic diisocyanate, an aliphaticdiisocyanate, an alicyclic diisocyanate.
 16. The dispersant for the fineparticles for the sintering according to claim 13, wherein the polyol isselected from the group consisting of polyether polyol, polyesterpolyol, acrylic copolymer including hydroxyl group.